GIT Knowhow - How to replace branches with tags?

gistfile1.eclass

## Given a git repo with at least one branch (for example "tags/A") 
## which should be transformed into a tag

for t in `git branch -r | grep tags | perl -pi -e "s/origin\///"`; do 
  echo ============================ $t  ; 
  REV=`git log -1 --pretty=%h   origin/$t`; 
  COMMENT=`git log -1 --pretty=%s  origin/$t`;  
  TAG=`echo $t | cut -d'/' -f2`; 
  echo $t .. $REV .. $COMMENT .. $TAG; 
  git tag -a $TAG -m "$COMMENT" $REV;  
  git push origin :refs/heads/$t; 
done

git push --tags